Madison, Wisconsin - Donated fat removed during liposuction and chemically treated to prevent rejection could become a viable source of repair tissue during neurological and other types of surgeries.

University of Wisconsin neurosurgeon John S. Kuo, MD, PhD, and colleagues report in a new study taking fat from donor rabbits, chemically treating it, and then implanting it into recipient rabbits.

Those who received the processed fat grafts showed good wound healing and little immune rejection, compared with those that received untreated fat grafts. The transplanted processed fat was accepted in recipients as well as, or better than, transplants of their own fat removed from elsewhere in the body.

Dr. Kuo, assistant professor of neurosurgery and director of the comprehensive brain tumor program at the UW School of Medicine and Public Health, reported the findings in the Dec. 4 edition of the Journal of Neurosurgery.

Kuo and other neurosurgeons often harvest fat from patients to help repair cerebrospinal fluid. These leaks are often caused by trauma or in the course of surgeries near the skull base to remove tumors such as pituitary tumors, acoustic neuromas or meningiomas. While fat can be harvested from a patient's abdomen, that requires another incision, more time on the operating table and increased infection risk.

Kuo said the idea came from Dr. Martin Weiss, his mentor and former chair of neurosurgery at the University of Southern California, who noted that the fat removed during liposuction was routinely discarded.

"We thought, there is all this fat going to waste, is there a way to make it useful?" Kuo said. "If you could clean, process and make fat non-immunogenic, then you could develop a product that you could get off the shelf when you needed it."

The key was treating the fat to reduce immune rejection by reducing grafts to an acellular matrix that is more easily taken up by the host. While the processed fat was well incorporated into the wounds during healing, untreated fat incited an acute immune response that also damaged adjacent host tissue.

In addition to neurosurgery, Kuo said that plastic surgeons also implant fat tissue, and that it might be useful for multiple purposes in wound healing. While more work needs to be done before testing in humans, the vision is to create a "tissue bank" of fat that has been processed to remove infectious and antigenic factors for use.

In addition to Weiss, Kuo's co-authors on the study were Drs. Cynthia Hawkins and James Rutka, both of the University of Toronto.